I see so, keyboard sheet should have both clefs and then immediately do clef change
– LennyFeb 12 at 5:14

2

Your question is not „ wrong“. Some composer write in such situations a violine clef for both hands. Especially in this case as it is collection of preludes for piano. I could see a reason: I had over looked the violin clef in Bartoks mikrkosmos “ in the mist.” My auntie got quite angry and upset about the dissonants. She said: Don’t you see, you’re playing the wrong clef! Thus I changed the clef and the sound was even more awful. Since then I became a Bartok fan: You can annoy aunties.
– Albrecht HügliFeb 12 at 5:33

Also keep in mind that the sheet music publisher is the one who did the typesetting, not the composer.
– Carl WitthoftFeb 12 at 13:29

1

@AlbrechtHügli "My auntie got quite angry and upset about the dissonants. She said: Don’t you see, you’re playing the wrong clef! Thus I changed the clef and the sound was even more awful. Since then I became a Bartok fan" I laughed
– user45266Feb 12 at 17:37